Question
A series LCR circuit with R = 20 Ω, L = 1.5 H and C = 35 μF is connected to a variable-frequency 200 V ac supply. When the frequency of the supply equals the natural frequency of the circuit, what is the average power transferred to the circuit in one complete cycle?
Solution
Given, a series LCR circuit.
Impedence , Z = 20Ω
Impedence , Z = 20Ω
Inductance, L = 1.5 H
Capacitance, C = 35 μF
When the frequency of the a.c. supply is equal to the natural frequency, then
Impedence is equal to resistance.
i.e.,
Then,
Hence, average power transferred
Capacitance, C = 35 μF
When the frequency of the a.c. supply is equal to the natural frequency, then
Impedence is equal to resistance.
i.e.,
Then,
Hence, average power transferred